A surface treatment apparatus for vehicle bodies which, by rotation about 180.degree., is dipped into a treatment bath or, by a counter-rotation, is removed again out of this, is known from GB 2 229 381. In this apparatus, a vehicle body is securely mounted by means of a type of loading pallet. This unit consisting of the loading pallet with the vehicle body mounted thereon is placed on a rolling carriage. This rolling carriage is in turn equipped with non-driven rollers which enable displacement transversally to the longitudinal axis of the vehicle body. By means of such a non-driven rolling carriage, the loading pallet is transported together with the vehicle body from the treatment bath to further processing stations.
The entire combination consisting of the vehicle body, the loading pallet and the rolling carriage is pushed onto a mounting which is arranged above each treatment bath. This mounting has a rotational axis arranged transversely to the longitudinal axis of the vehicle body and parallel to the transport direction. By rotation about this rotational axis by 180.degree., the entire combination consisting of the vehicle body, the loading pallet and the rolling carriage can be dipped into the treatment bath. During this submerging process, the mentioned mounting and the unit consisting of the vehicle body, the loading pallet and the rolling carriage are connected with each other by means of locking bolts.
In order to transport the vehicle bodies or the rolling carriage, respectively, a conveyor belt is provided which extends through several treatment stations having an associated treatment bath. These treatment stations lie side-by-side and the conveyor belt transports the rolling carriage, on which a loading pallet with the vehicle body is respectively mounted, from one treatment basin to another treatment basin. For this purpose, vertically standing pallet parts which lie against the rolling carriage are mounted on the conveyor belt. This type of apparatus for introducing a vehicle body has the advantage that slopping of the treatment liquid in the treatment bath is minimized by means of a simple mechanism in that the vehicle body is rotated into the treatment path via the front or rear side. The volume of air locked in the vehicle body can then continuously escape out of the windows of the vehicle body during the rotating process.
The construction of this apparatus is relatively complicated and only suitable for very small units. When a vehicle body has to be dipped, the next vehicle body must wait until the processing time of the first body has expired. This processing time lasts up to three minutes in the case of pre-treatment in individual processing steps and even longer in cathodic dip-coating.